Modern motor vehicles are fitted with numerous electronic stations or functions, some of which must be capable of being active when the engine is stopped. By way of example, mention may be made of controlling lighting, fog lights, windscreen wipers, monitoring liquid levels, temperature levels, speed, ABS functions, suspension controlling functions, and functions that must be capable of remaining active when the engine is stopped: door control functions, warning light functions, alarm systems.
The introduction of electronics into the automobile industry has led the ISO to propose a limit of 1 mA on electricity consumption when the engine is not operating, for the purpose of avoiding premature discharge of the vehicle battery.
Given the state of the art, it would appear to be difficult to satisfy this condition while keeping all of the electronic stations or functions switched on.
Proposals have therefore been made to switch off power supply to at least some of these stations when the engine is stopped.
More precisely, proposals have been made to design electronic stations capable of occupying two different operating modes or states: an active mode in which all of the means of the station required for performing a function are in operation, and a dormant mode in which the only portion of the station that remains in operation is the portion required for "waking it up".
These proposals constitute the subject matter of literature which is already fairly abundant.
By way of example, the following documents may be mentioned: FR-A-2508257, FR-A-2578070, FR-A-2626998, FR-A-2627036, FR-A-2627038, FR-A-2627039, and GB-A-2172727.
However, prior proposals do not give full satisfaction.
A particular object of the present invention is to provide a method of controlling a network of electronic stations which enables stations to switch between active mode and dormant mode under optimum conditions.